Porsche 996 cup car

[spiller]

Saw this out at AMF. Looks awesome dude. Such a great event!

Cheers dude. Hoping they extend the track for this year, there’s been some talk of turning left after the chicane instead of right.

Fixed

^^^ lol


Thanks to McMulla who is an absolute legend and spent considerable time scanning through his old Motorsport mags from 2003-05 to send me all of the race reports and any relevant pics. He also managed to fine a handful of old race footage.


^^^ the team wore this Mossimo livery for about the first half of 2003 before Braun came onboard. Peter Hill (founder of Globe) was a driver and I think he had something to do with Mossimo.


^^^ this was fortunately not the car I have. Shannon O’Brien stood in for Alan Gurr at Bathurst in 2005 and managed to barrel roll through the chase. Needless to say that car was retubbed.


A pic of the first batch of cars on their arrival into Aus in early ‘03.

[darkside]

This is awesome. A car with proper race pedigree and a history. Top effort digging it all up.

[spiller]

I decided to do a few small jobs yesterday on the car in prep for next weekend’s Porsche Club supersprint.

Job 1 was to replace the oil pressure sender. It’s quite common for this part to fail on 996 and 997 models of all kinds, usually resulting in the oil pressure gauge reading zero. In my case the opposite has happened and it’s reading maximum at all times. The motec data also reads maximum which confirms it’s not the gauge that is faulty.

$165 part but fortunately only a 5 minute job to replace. Easy access with a 19mm spanner to crack it and was able to reach in and undo by hand. I am learning that the 996 cup is a rather easy car to do most things on given there isn’t much in the engine bay.





^^ new part on the left, old on the right. The part number has changed by one digit so I can only assume Porsche have updated the faulty part with a different design.

Job 2 was to replace the fuel filter. The road car interval is 6 years or 40K miles. I would assume the cup car is shorter, maybe a once a year thing or something if racing lots of kms per year.

I first wanted to make sure I didn’t spill fuel everywhere. The cups have a fuel drain point and a switch to run the pump so I decided to empty the 10L or so of fuel out of the tank first. Not essential but I hadn’t tried it before so why not.

Step 1. Locate the drain point


Beneath the black rubber cap is a quick disconnect fitting.


Hose hooked up and into the can. Numb nuts still
managed to allow the hose to exit the can prematurely, spilling fuel!


After getting the old filter out (10 minute job) the date shows it’s just a little past the interval. Not surprising given it sat for 9 years.


I decided to cut the old filter open for a look inside. It actually wasn’t visibly dirty, discoloration is from my hacksaw blade. Regardless, I’m glad a new one is in place. When I have more time, I will pull the injectors and send them out for service as they’ve probably never been done.


Final job was to bleed the brake fluid. First time I’ve used a Motive Power Bleeder and I don’t know why I waited so long to buy one. Bleeding was a breeze and I could take my time. Brakes were last bled about 6 months ago and the fluid in the calipers was noticeably dirty but ran clear and bubble free very quickly. Having seen this I’ll probably just hook up the bleeder before every event from now on.


Can anyone tell me a reasonable shelf life of brake fluid once you’ve cracked the seal on the container? SRF is $120/L and I have 500mL left so would rather not waste it if I can avoid it.

The only issue I encountered was that one bleed nipple was very rounded and difficult to nip up to a tightness I’m comfortable with. I’ll grab a new one from the dealer this week and throw it in before Sunday.

Someone (Greg Rust) commented that they were keen to see some suspension pics earlier in the thread....

This is the rear set up. They run a Sachs 2 way damper with helpers and remote reservoirs.



And a shot of the rear brake ducts. The 996 cup and GT3 did not come standard with rear brake ducts, however the 996 GT2 did, and they fit with ease. I had these on my road car and pulled them off before selling it as I was hoping I’d get a cup car at some stage.


The front damper/spring set up is a little different in that the fluid reservoir is mounted to the shock body. The front strut on these cars can be rotated in order to gain more negative camber, then shims are used to fine tune.


The cup also runs a centre lock wheel. These are really quick and easy to operate. Nip them up with a lithium rattle gun and torque to 460 Nm. Porsche also recommends cleaning the stub axle threads, wheel washer and wheel nut before applying copper grease to all mating surfaces every time you replace the wheels in a driving situation.


And a pic of the front brake ducts. These are enlarged over the standard GT3 ducts with an extended section riveted on. They hang really low and cop a beating (hence the cable ties for added security). Porsche charges about $450 for a pair!! Expensive plastic but I have three full sets (I had two pairs left over from what I had previously fitted to my road car) and hopefully never have to buy another one.


Over the past few weeks, McMulla being the absolute champ he is has been going over many old motorsports magazines and scanning anything pertaining to my car, Greg Murphy Racing and 996 era Carrera Cup in general. Thanks to him, I now have 150-200 magazine clippings which I’m very thankful for. He even managed to find a pic of the car being raced by the guy who I bought it from. This was early 2006 shortly after he acquired it from GMR. Up until now, I only had pics of the car painted entirely blue in his hands and wondered how and when this came to be. I reached out to the P.O. to ask if the car was all blue when he first bought it from GMR of if it had remnants of the old Glenfords livery. I never heard back from him. He paid $135K or there abouts in late 2005.



Due to lack of pics, I never had any actual evidence that my car was in fact the yellow and red Ian Dyk car other than what the previous owner had told
me. He admitted he wasn’t that good at keeping records and since there were two other Glenfords cars, you just never know. I had discovered some remnants of yellow and red in certain areas on the car (insides of the mirrors, for example) but teams have been known to swap parts between cars. Example, the 14 wheels I have come from all three of the cars GMR ran in 2003-2005. I know this as each wheel was marked according to the race number of the car it belonged to. Anyhow, I digress! The pic above confirms that mine is the ex-Dyk car. If you haven’t noticed by now, I love tracking history on everything so the pic above was great to see. Thanks again McMulla!

[burn is weird]

Castrol SRF has an epic wet boiling point so the shelf life issue is far reduced compared to the cheaper dot 5.1 race fluids that are initially great then go to shit when "wet"

its the main reason to use it, you can leave it in for the year and even if its saturated it still performs amazingly well. if you were going to fully flush it every event then you'd just use a cheaper fluid with a higher dry boil rating.

however, i still store mine in a flexible bottle and squeeze all the air out before tightening the cap as I tend to use a bit over a litre for a full flush and need to buy two 1L bottles at a time (ouch)

[spiller]

Castrol SRF has an epic wet boiling point so the shelf life issue is far reduced compared to the cheaper dot 5.1 race fluids that are initially great then go to shit when "wet"

its the main reason to use it, you can leave it in for the year and even if its saturated it still performs amazingly well. if you were going to fully flush it every event then you'd just use a cheaper fluid with a higher dry boil rating.

however, i still store mine in a flexible bottle and squeeze all the air out before tightening the cap as I tend to use a bit over a litre for a full flush and need to buy two 1L bottles at a time (ouch)

Yep that was my understanding on why SRF is so good too. When I say before every event, I mean just to expel the fluid in the calipers, not a full flush. Probably only use 350mL of fluid each time so I figure a bottle should last me the best part of 12 months. Should be ok if stored indoors and air squeezed like you said?

[burn is weird]

I reckon.

you could always test some in a small saucepan with a thermocouple in it after 12 months if you're the science experiment type.

should be fine. keep moisture, UV light and gas atmosphere away from it and I can't see why it would degrade, and its certainly better off than the fluid sitting in your master cylinder reservoir that you're about to push into your lines during the bleed anyway.

[Greg Rust]

Excellent thanks for the pics. Very cool.

[spiller]

...and its certainly better off than the fluid sitting in your master cylinder reservoir that you're about to push into your lines during the bleed anyway.

When you put it that way, it’s a no brainer!

Excellent thanks for the pics. Very cool.

No probs mate

[Race Spec]

Loving the detailed updates, comparisons between the road and race car and the history of the car.

... in prep for next weekend’s Porsche Club supersprint.

I am giving the Evo a run too on Sunday, so I'll see you on the grid from my rear view mirror. Hoping for a cool change tho!

[Bob Vegana.]

This might be of interest to you:

http://www.webbimages.co.uk/chassisindexpage.htm

[spiller]

Loving the detailed updates, comparisons between the road and race car and the history of the car.



I am giving the Evo a run too on Sunday, so I'll see you on the grid from my rear view mirror. Hoping for a cool change tho!

Cool, should be fun! I think you'll be paired with Willall lambo on the front. I'll prob be dicing with some GT3RS in that case.

This might be of interest to you:

http://www.webbimages.co.uk/chassisindexpage.htm

Thanks for that, very interesting. Will take a look.

[BLO 767]

Nice updates man. x2 on the power bleeder - I bought the SP Tools one after headaches bleeding my Tilton setup. Quite possibly the single best car tool I've ever bought.

Very much OK to use that fluid also, as said. The serious guys change fluid as often as they put fuel in the bloody things.

[spiller]

Nice updates man. x2 on the power bleeder - I bought the SP Tools one after headaches bleeding my Tilton setup. Quite possibly the single best car tool I've ever bought.

Very much OK to use that fluid also, as said. The serious guys change fluid as often as they put fuel in the bloody things.

Thanks mate. Out of curiosity, do pro teams do a complete fluid flush every time or just get rid of the shit stuff in the calipers?

I have been comparing my data against Ian Dyk's (I got all of his Data from 2005 with the car, along with set up sheets for his and Coulthard). On the main straight at Adelaide, Dyk was doing 195 kph by the braking point for T1 after a minimum speed of 62 kph out of the final turn. My best was 168 kph with a similar minimum speed out of the final corner. He had a freshly rebuilt engine at the time which has since done approx 5000 kms. 23 km/h difference seems substantial in just a straight line situation. My throttle position data is reading 92% at max so possibly giving up a few ponies there and may need to look at re-calibrating the TPS...

[Guido]

You may also have been braking a lot earlier.

[BLO 767]

Thanks mate. Out of curiosity, do pro teams do a complete fluid flush every time or just get rid of the shit stuff in the calipers?

I have been comparing my data against Ian Dyk's (I got all of his Data from 2005 with the car, along with set up sheets for his and Coulthard). On the main straight at Adelaide, Dyk was doing 195 kph by the braking point for T1 after a minimum speed of 62 kph out of the final turn. My best was 168 kph with a similar minimum speed out of the final corner. He had a freshly rebuilt engine at the time which has since done approx 5000 kms. 23 km/h difference seems substantial in just a straight line situation. My throttle position data is reading 92% at max so possibly giving up a few ponies there and may need to look at re-calibrating the TPS...

Post Every session = caliper bleed.

Post Every race = full flush.

But every event would be fine for a weekender, usually pre-event when you do an alignment and susp check.

I'd hazard a statement that you'll never hit chassis PB's in a car past its top tier days, but it could be plenty of things. Different tyre spec' rolling resistance, old transaxle resistance, grip under throttle, brakes etc. Throttle map is definitely something to check esp on cars that get constant engine in / out and service intervals. But full race cars that live under WOT under track conditions just get slower the older they get, the more they are rebuilt. Usually engine related, but also chassis too.

[Nafe]

Epic thread. I might have pics of it from it's GT3 Cup Challenge days, but doubtful from earlier. I'll dig around when I get a chance and you can have whatever I've got of it.

[spiller]

Post Every session = caliper bleed.

Post Every race = full flush.

But every event would be fine for a weekender, usually pre-event when you do an alignment and susp check.

I'd hazard a statement that you'll never hit chassis PB's in a car past its top tier days, but it could be plenty of things. Different tyre spec' rolling resistance, old transaxle resistance, grip under throttle, brakes etc. Throttle map is definitely something to check esp on cars that get constant engine in / out and service intervals. But full race cars that live under WOT under track conditions just get slower the older they get, the more they are rebuilt. Usually engine related, but also chassis too.

Hmm yep, that all makes sense. Add to all of that, the fact that one is a pro and the other is a hack () and it starts to add up. Maybe I’m expecting too much from the old girl. Tell me more about transaxle resistance? Something something about parts creating more “ drag” (for want of a better word) as they wear? Another thing which I forgot to mention which I believe would play a part is the wing settings. I went back through Dyk’s data and checked his speed in each gear against my data to check if I still have the same gearing. Gearing appears to be the same, however I noticed at Adelaide ‘05, Dyk’s speed at 7100 rpm in 5th was 218 km/h versus me doing 208 km/h at the same RPM. I have only ever run the car with the wing in maximum setting. For further comparison, I checked his data for Bathurst of that year...208 km/h at 7100 rpm! Obviously they ran max aero at Bathurst for across the top of the mountain and presumably less wing at Adelaide which is very much a mechanical grip circuit. Interestingly, I was always fastest in my GT3 at Mallala with the factory wing as opposed to the larger RS wing. An American magazine did a comparison of the road GT3 versus the cup back in 2003 at Daytona and the road car trapped higher every time. I’ll have to remember to adjust the wing to a less aggressive setting before I go out on Sunday.

So, all things considered:

-pro driver versus amateur
-engine probably not as strong due to normal accumulation of miles
-chassis wear and tear etc
-wing settings
-driver weight (Dyk 66kg vs me 90kg)

I guess 23 km/h is not too bad

You may also have been braking a lot earlier.

Undoubtedly I would have been, he also carried 10 km/h more through the Senna Chicane on most laps compared to me. No 10/10ths into and through there for me, seen too many bounce off the curb into the left hand wall (namely a 675LT in 2017 at the hands of a professional driver).

Epic thread. I might have pics of it from it's GT3 Cup Challenge days, but doubtful from earlier. I'll dig around when I get a chance and you can have whatever I've got of it.

Thanks mate. I think the car only did just the one cup challenge round, which was the 2009 Bathurst 12 Hour. If you happen to have anything that would be awesome!


In other news I got a call from Matt House today. He was the team manager for Glenfords GMR in their Carrera Cup days and works for Kelly Racing. He was able to confirm some of the engine work done to the car previously and also told me Oakeshott actually owned the car all along and was the one who forked out for all of the maintenance and was very fussy. Apparently Oakeshott leased the car back to GMR for the 2005 season as he wasn’t driving that year and they then sold it (to the previous owner) on behalf of him. I coincidentally know Oakeshott’s daughter so I will try and get him on the phone at some stage to see if he can provide any further history. That will be the absolute last avenue for all and any history possible on the car so will be good to tick that box.

[Nafe]

Do you know what was the last year of Carrera Cup it raced? I may have some stuff from earlier than 2009.
I definitely have the 2009 GT3 Cup Challenge stuff from Bathurst.

[spiller]

‘05 was its last year in CC

[BLO 767]

Hmm yep, that all makes sense. Add to all of that, the fact that one is a pro and the other is a hack () and it starts to add up. Maybe I’m expecting too much from the old girl. Tell me more about transaxle resistance? Something something about parts creating more “ drag” (for want of a better word) as they wear?

In other news I got a call from Matt House today. He was the team manager for Glenfords GMR in their Carrera Cup days and works for Kelly Racing. He was able to confirm some of the engine work done to the car previously and also told me Oakeshott actually owned the car all along and was the one who forked out for all of the maintenance and was very fussy. Apparently Oakeshott leased the car back to GMR for the 2005 season as he wasn’t driving that year and they then sold it (to the previous owner) on behalf of him. I coincidentally know Oakeshott’s daughter so I will try and get him on the phone at some stage to see if he can provide any further history. That will be the absolute last avenue for all and any history possible on the car so will be good to tick that box.

Pretty much bang on man. Spherical bearing wear, shaft wear, seal wear, gear wear, anything allowing micro-walking, friction and drag. When the NASCAR guys would qualify on the fastest oval tracks, they'd even press the pads back in the calipers to take resistance off the discs to get that extra mph. Just had to remember to pump them back up before pit road!

You can replace everything mechanical on the car to make it as new as possible, but then there's still the general chassis fatigue. People often mistakingly think that adding stiffness to a chassis instantly adds strength and longevity. But on the contrary, a full race car chassis (especially) becomes a consumable item. Back in my vehicle builder trade days we had a saying: There is no perfect chassis. The only perfect chassis is the one that hasn't been used. A chassis is already in a state of 'damage', if you will, on its first or second outing.

Also, cool detective work jeeves Oake must have had some serious coin to dump into this bad boy!

[spiller]

^^^ very interesting! And let’s be honest, it would have been knocked about a bit in its competition life as they all have. Speaking of resistance on brake discs, rebuilding the calipers is on my short list as sitting for 10 years wouldn’t have been much good for them and I have noticed one or two wheels are a little bit more difficult to turn by hand than I’d like them to be.

[darkside]

Man,

I would hate to have data of a pro driving my car. Would shatter all the dreams. But flip side I guess is it gives you something to shoot for. That discrepancy does seem a bit. Do you have a throttle and brake trace? As others have said, while absolute min corner speed is the same, he might be picking up the gas earlier and braking later ? Maybe you could pick two points on a straight to see if the rate of acceleration as opposed to absolute speed varies much to get some insight into whether it’s more about a few horses escaping the paddock or something else.

Love the other cool proper race car features of these like the fuel drain etc and being built to be worked on easily. Just such a well engineered proper race car.

[spiller]

Yep it tells you throttle and longitudinal G (instead of brake pressure) but I’m not that good at reading that stuff. It would be great to sit down with someone who knows exactly what they’re looking at and overlay the two samples to directly compare. Still it’s good fun learning and trying to work through it yourself. Buik is very good at data coaching so I might chat to him and see if he will look at both sets to give a better understanding of what’s going on. Speak of the reference points, Dyk shifts gears at an earlier reference point each time than I do (but we both shift at the same rpm) so I think acceleration is the biggest thing here. Could be the throttle map, I’ll have that looked at. I’m sure just some normal loss of HP too but by many accounts the mezger engine does not drop considerable HP as the engine ages. Lots of reports of engines in the states running 15,000-20,000 km+ without significant loss of HP. Porsche recommended engine service interval is 5-6000 kms which is evidently very conservative.

[Gammaboy]

I guess 23 km/h is not too bad

He may also have been getting a tow from the car infront.

[darkside]

^^^ Hadn’t thought of that. That could definitely account for a chunk of it.

I, like you, find the data analysis overwhelming. But am keen to do more of it as the more I do it, the more it seems easier to interpret.

[Guido]

23km/h is a massive difference for the same car. Given other variables are all the same (which they can't be), you'd be looking at a significant power difference.

So I think it's probably a combination of:

* misinterpretation of data
* age issues of GPS
* different gearing
* different shift points
* picking up the throttle much earlier (fresh tyres, pro driver, track conditions - I imagine a lot of rubber would have been laid down back then)
* getting a tow from another car
* braking later

[spiller]

The 996 cup motec doesn’t run a gps and cannot be adapted to suit as it was pre ADL1. It pulls the speed from three wheel speed sensors. I agree, pretty hard to compare apples to apples with limited info. I’ll never know until I run the car on the dyno to check its HP numbers. Dyno read outs can be misleading too though so where do you stop.

As above, gearing is the same, shift points are the same or similar enough. If it were 10km it might be legitimate. Remember we are only talking about a small % of the lap distance that I’m analyisng here.

[Guido]

It's not something you really should be concerned about anyways. The car would be soooo fucking fun to drive and you're probably going to make bug advancements in speed each time you step in to the silly seat.

[spiller]

Yeah not overly concerned, but more so curious. The power band has never felt quite as strong as the road car I had but this thing more than makes up for it in corners .

Started the car today to check the reading on the oil pressure gauge. Farkin thing is still maxing out with motec doing the same at 11bar. I struggle to believe it’s running that much pressure but going to throw a mechanical gauge on it tomorrow just to be safe before Sunday’s event.

[BLO 767]

Starting a Cup car in a residential garage is goals.

Pressure relief valve? Surely that's max reading @ 150psi +. I have a similar wallet-draining-exy MoTeC OPG - does it need calibrating in the MoTeC?